Manufacturing incandescence bodies.



WALDEMAR BRUNO, OF BERLIN, GERMANY.

MANUFACTURING INCANDESCENCE BODIES.

No Drawing.

Specification of Letters Patent.

Application filed July 6, 1909.

Patented Jan. 28, 1913.

Serial No. 506,030.

To all whom it may concern:

Be it known that I, WALDEMAR BRUNO, engineer, residing at N. Liebenwalderstrasse 10, Berlin, Germany, have invented certain new and useful Improvements in the Manufacturing of Incandescence Bodies; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to the manufacture of incandescent bodies for gas burners, from artificial filaments, to which the requisite salts of the rare earths are applied in the form of solutions, as in the case of incandescent bodies of cotton or other vegetable fibers.

The impregnation of incandescence bodies of artificial filaments does not itself present any difficulty, but considerable difficulties have been encountered in the burning of such bodies, owing to the absence of a strong skeleton of ash, and to the conversion of nitrates into oxids, accompanied by swelling injurious to the structure. To obviate this it is essential to arrange that the formation of oxid is not due solely to the action of the flame, but is at least in part procured in advance with the aid of suitable chemical reactions. By this means there is formed a skeleton consisting of the oxids or hydrates of the salts which very quickly bakes or fuses together in the flame and gives the necessary strength to the structure.

This process consists in treating the im pregnated mantles in a bath at a temperature of about 40 or 50 C. This bath consists of a mixture of alkalis or amins and acid which are capable, with cooperation of the bases, to convert the nitrates into basic double compounds. Acetic acid, oxalic acid and other organic acids may be used; also phenols. The alkalis or amins used must form volatilizable compounds and soluble compounds with the said acids and with the nitric acid of the salts of the rare earths. The formation of the basic double compounds is materially favored by immersing the moist fabric into the heated solutions of alkali or amin at the moment at which the acid is added, and at which considerable heat of formation is evolved. The conversion of the nitrates into insoluble or nearly insoluble compounds takes place almost instantaneously, so that no lixiviation of salts can take place. If the alkalis or amins are present in excess the basic double salts are more or less converted into oxids or hydrates. The employment of an excess of alkali is, however, not necessary since when the body is ignited the basic double salts are easily converted into oxids of the rare earth metals, without swelling, since the acids used are easily vaporizable.

A suitable bath for treating the impregnated fibrous fabric is prepared as follows: Two kilograms of crystallized oxalic acid are dissolved in twenty kilograms of distilled water at a temperature from 70 to 75 C. and ten kilograms of liquid ammonia of normal temperature are added to this solution. At the moment, when the chemical action takes place in the so prepared bath (which consists of the compounds of the chemical combination of oxalic acid with the alkali), the impregnated stockings are thrown in and properly immersed in the solution. At this point the solution must be kept at a temperature between 40 to 50 C. The mantles are kept in the solution at this temperature for about two minutes. (It may be noted that at 37 C. the salts are precipitated.)

The incandescence bodies produced are of greattensile strength capable of bearing 50 to grams and are elastic and flexible.

Since the final treatment takes place in amt u nascemli, the chemical reactions are rapid. Consequently there is no loss of rare earths, and the bodies are of extremely uniform composition, and are also characterized by great uniformity of lighting power. The rapidity of the reaction is increased by the treatment of the bodies in a somewhat moist state, as described.

Having thus described my invention, I declare that what I claim as new and desire to be secured by Letters Patent is:

A process for makingincandescence bodies from artificial filaments, which consists in first impregnating the filaments with the requisite nitrates of the rare earths, then 7 compounds with the nitric acid of the salts In testimony whereof I mysignalture, 1n presence of two wltnesses.

WALDEMAR BRUNO.

\Vitnesses VVOLDEMAI: HAUPT, HENRY HASPER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latents, Washington; D. O. 

